Conventional compression couplings used for joining two tubes together are typically designed with three parts that thread together, with one of the parts being a left end “nut”, another part being a central “body” and a third part being a right end “nut”. Typically, both end nuts contain gaskets and internal threads that are threaded onto external threads formed on the central body. To produce these components, four separate threading operations are required in the manufacturing of the three parts, and all three parts must be made of material sufficiently strong to prevent stripping of the threads or other damage to the threads. It would be desirable to reduce the number of threads that must be produced on the parts, as well as to reduce the number of thread engagements that must be manipulated in order to join two tubes via a coupling.